Does intelligence require a nervous systems? (Parameciums, plants, etc..)

With the rise of artificial intelligence (AI), researchers have postulated whether it demonstrates true intelligence or not. Considering cognition throughout nature, intelligence can be observed outside of the complex nervous systems that are seen in humans and animals. By looking at the behavior of paramecium, known for their primitive nervous systems, and plants, who lack nervous systems, we can analyze the existence of intelligence beyond neural networks.

Paramecium are single celled organisms that exhibit information processing and storage, which is suggested to be facilitated via their microtubules. In Paramecium caudatum, intelligent behaviors, such as associative learning, have also been witnessed. To test the correlation between intelligence and microtubules, a recent study assessed the effect of inhibiting microtubule functioning via a partial allosteric modulator of GABA on information processing. The results indicated another mechanism may be at play, as the antimicrotubule agent did not interfere with learning by the paramecium.

To better understand the structure of information networks within plants, plant neurobiology was established. Information networks produce adaptive intelligent behaviors in plants, including plant movement and signal integration, root decisions and self-acquaintance, and plant-level communication. These behaviors are thought to mediated by ‘root brains’ that integrate and transmit information in neuron-like manners. At the root apex, brain-like units are interconnected by vascular stands that act like neurons with polarity-transported auxin that serve as plant neurotransmitters to create a neuronal system of plants.

Although intelligence in humans is dependent on the nervous system, intelligence can also be established without a nervous system as in paramecium and plants. Because of these findings, the notion that AI may be able to mimic human intelligence so well in the future that it becomes indistinguishable is an interesting idea. Nonetheless, we can still turn to organisms outside of the animal kingdom to continue to study the various mechanisms that result in intelligence.

Sources:

Garzón, P. C., & Keijzer, F. (2011). Plants: Adaptive behavior, root-brains, and minimal cognition. Adaptive Behavior

Alipour, A., et al. (2022). Microtubule Disruption Without Learning Impairment in the Unicellular Organism, Paramecium. Basic and clinical neuroscience